I have tried a lot of e liquids on e bay and I've had some nightmares but I can honestly say that the Diamond Mist range is by far the best brand of e liquid on the market and it's very reasonably priced.
I would definitely recommend this brand as the usual cheaper ones are usually very poor quality.
I have been vaping now for over 3 years and I've tried a lot of brands that I don't think are genuine e liquids for the brand they are selling under but I've found that the Diamond Mist are always what they are sold as ie Genuine Diamond Mist e liquids if you understand what I mean.